The general goals are to examine the relationships between structure and function in the primate neostriatum and to provide a better understanding of the nature and mechanisms of sensorimotor integration in the putamen. Recent studies have revealed physiologic inhomogeneities within the primate putamen in the form of 1) discrete clusters of neurons whose activity is related to movements and/or somatosensory stimulation of individual body parts, or whose activity exhibits instruction-dependent changes in discharge related to "motor set" and 2) discrete foci, "striatal microexcitable zones" (SMZ), from which movements of individual body parts may be evoked by microstimulation. The specific aims are to determine the relationships between these physiologic inhomogeneities and the recently described anatomical inhomogeneities within the striatum, which occur in the form of discontinuous patches of terminal labeling of cortical and thalamic afferents and discontinuities in the distribution of histochemical, histofluorescence and immunocytochemical markers for a variety of neurotransmitter/neuromodulators. These discontinuities appear to reflect an intrinsic organization of the neostriatum in the form of two interdigitating compartments which, in the primate, have been designated the "island" and "matrix" compartments. The studies are designed to evaluate the relationships between the anatomic and physiologic compartments of the primate putamen, and between this intrinsic organization and the patterns of striatal afferent and efferent connections. Specifically, we plan to investigate the patterns of termination of striatal afferents from the motor, premotor and somatosensory cortex and the supplementary cortex and the organization of putamen output neurons projecting to the globus pallidus and the substantia nigra. These studies employ techniques of single cell recordings from behaving primates, anterograde and retrograde transport studies, immunocytochemical and conventional anatomical techniques. These studies should help to clarify the functional organization of the basal ganglia and may lead to a better understanding of the role of these studies in health and disease.